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16#include <linux/module.h>
17#include <linux/random.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/wait.h>
21#include <linux/vmalloc.h>
22
23#include <net/addrconf.h>
24#include <net/inet_connection_sock.h>
25#include <net/inet_hashtables.h>
26#include <net/secure_seq.h>
27#include <net/ip.h>
28#include <net/tcp.h>
29#include <net/sock_reuseport.h>
30
31static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
32 const __u16 lport, const __be32 faddr,
33 const __be16 fport)
34{
35 static u32 inet_ehash_secret __read_mostly;
36
37 net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
38
39 return __inet_ehashfn(laddr, lport, faddr, fport,
40 inet_ehash_secret + net_hash_mix(net));
41}
42
43
44
45
46u32 sk_ehashfn(const struct sock *sk)
47{
48#if IS_ENABLED(CONFIG_IPV6)
49 if (sk->sk_family == AF_INET6 &&
50 !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
51 return inet6_ehashfn(sock_net(sk),
52 &sk->sk_v6_rcv_saddr, sk->sk_num,
53 &sk->sk_v6_daddr, sk->sk_dport);
54#endif
55 return inet_ehashfn(sock_net(sk),
56 sk->sk_rcv_saddr, sk->sk_num,
57 sk->sk_daddr, sk->sk_dport);
58}
59
60
61
62
63
64struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
65 struct net *net,
66 struct inet_bind_hashbucket *head,
67 const unsigned short snum)
68{
69 struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
70
71 if (tb) {
72 write_pnet(&tb->ib_net, net);
73 tb->port = snum;
74 tb->fastreuse = 0;
75 tb->fastreuseport = 0;
76 tb->num_owners = 0;
77 INIT_HLIST_HEAD(&tb->owners);
78 hlist_add_head(&tb->node, &head->chain);
79 }
80 return tb;
81}
82
83
84
85
86void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
87{
88 if (hlist_empty(&tb->owners)) {
89 __hlist_del(&tb->node);
90 kmem_cache_free(cachep, tb);
91 }
92}
93
94void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
95 const unsigned short snum)
96{
97 inet_sk(sk)->inet_num = snum;
98 sk_add_bind_node(sk, &tb->owners);
99 tb->num_owners++;
100 inet_csk(sk)->icsk_bind_hash = tb;
101}
102
103
104
105
106static void __inet_put_port(struct sock *sk)
107{
108 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
109 const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
110 hashinfo->bhash_size);
111 struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
112 struct inet_bind_bucket *tb;
113
114 spin_lock(&head->lock);
115 tb = inet_csk(sk)->icsk_bind_hash;
116 __sk_del_bind_node(sk);
117 tb->num_owners--;
118 inet_csk(sk)->icsk_bind_hash = NULL;
119 inet_sk(sk)->inet_num = 0;
120 inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
121 spin_unlock(&head->lock);
122}
123
124void inet_put_port(struct sock *sk)
125{
126 local_bh_disable();
127 __inet_put_port(sk);
128 local_bh_enable();
129}
130EXPORT_SYMBOL(inet_put_port);
131
132int __inet_inherit_port(const struct sock *sk, struct sock *child)
133{
134 struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
135 unsigned short port = inet_sk(child)->inet_num;
136 const int bhash = inet_bhashfn(sock_net(sk), port,
137 table->bhash_size);
138 struct inet_bind_hashbucket *head = &table->bhash[bhash];
139 struct inet_bind_bucket *tb;
140
141 spin_lock(&head->lock);
142 tb = inet_csk(sk)->icsk_bind_hash;
143 if (unlikely(!tb)) {
144 spin_unlock(&head->lock);
145 return -ENOENT;
146 }
147 if (tb->port != port) {
148
149
150
151
152
153 inet_bind_bucket_for_each(tb, &head->chain) {
154 if (net_eq(ib_net(tb), sock_net(sk)) &&
155 tb->port == port)
156 break;
157 }
158 if (!tb) {
159 tb = inet_bind_bucket_create(table->bind_bucket_cachep,
160 sock_net(sk), head, port);
161 if (!tb) {
162 spin_unlock(&head->lock);
163 return -ENOMEM;
164 }
165 }
166 }
167 inet_bind_hash(child, tb, port);
168 spin_unlock(&head->lock);
169
170 return 0;
171}
172EXPORT_SYMBOL_GPL(__inet_inherit_port);
173
174static inline int compute_score(struct sock *sk, struct net *net,
175 const unsigned short hnum, const __be32 daddr,
176 const int dif, bool exact_dif)
177{
178 int score = -1;
179 struct inet_sock *inet = inet_sk(sk);
180
181 if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
182 !ipv6_only_sock(sk)) {
183 __be32 rcv_saddr = inet->inet_rcv_saddr;
184 score = sk->sk_family == PF_INET ? 2 : 1;
185 if (rcv_saddr) {
186 if (rcv_saddr != daddr)
187 return -1;
188 score += 4;
189 }
190 if (sk->sk_bound_dev_if || exact_dif) {
191 if (sk->sk_bound_dev_if != dif)
192 return -1;
193 score += 4;
194 }
195 if (sk->sk_incoming_cpu == raw_smp_processor_id())
196 score++;
197 }
198 return score;
199}
200
201
202
203
204
205
206
207
208
209struct sock *__inet_lookup_listener(struct net *net,
210 struct inet_hashinfo *hashinfo,
211 struct sk_buff *skb, int doff,
212 const __be32 saddr, __be16 sport,
213 const __be32 daddr, const unsigned short hnum,
214 const int dif)
215{
216 unsigned int hash = inet_lhashfn(net, hnum);
217 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
218 int score, hiscore = 0, matches = 0, reuseport = 0;
219 bool exact_dif = inet_exact_dif_match(net, skb);
220 struct sock *sk, *result = NULL;
221 u32 phash = 0;
222
223 sk_for_each_rcu(sk, &ilb->head) {
224 score = compute_score(sk, net, hnum, daddr, dif, exact_dif);
225 if (score > hiscore) {
226 reuseport = sk->sk_reuseport;
227 if (reuseport) {
228 phash = inet_ehashfn(net, daddr, hnum,
229 saddr, sport);
230 result = reuseport_select_sock(sk, phash,
231 skb, doff);
232 if (result)
233 return result;
234 matches = 1;
235 }
236 result = sk;
237 hiscore = score;
238 } else if (score == hiscore && reuseport) {
239 matches++;
240 if (reciprocal_scale(phash, matches) == 0)
241 result = sk;
242 phash = next_pseudo_random32(phash);
243 }
244 }
245 return result;
246}
247EXPORT_SYMBOL_GPL(__inet_lookup_listener);
248
249
250void sock_gen_put(struct sock *sk)
251{
252 if (!atomic_dec_and_test(&sk->sk_refcnt))
253 return;
254
255 if (sk->sk_state == TCP_TIME_WAIT)
256 inet_twsk_free(inet_twsk(sk));
257 else if (sk->sk_state == TCP_NEW_SYN_RECV)
258 reqsk_free(inet_reqsk(sk));
259 else
260 sk_free(sk);
261}
262EXPORT_SYMBOL_GPL(sock_gen_put);
263
264void sock_edemux(struct sk_buff *skb)
265{
266 sock_gen_put(skb->sk);
267}
268EXPORT_SYMBOL(sock_edemux);
269
270struct sock *__inet_lookup_established(struct net *net,
271 struct inet_hashinfo *hashinfo,
272 const __be32 saddr, const __be16 sport,
273 const __be32 daddr, const u16 hnum,
274 const int dif)
275{
276 INET_ADDR_COOKIE(acookie, saddr, daddr);
277 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
278 struct sock *sk;
279 const struct hlist_nulls_node *node;
280
281
282
283 unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
284 unsigned int slot = hash & hashinfo->ehash_mask;
285 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
286
287begin:
288 sk_nulls_for_each_rcu(sk, node, &head->chain) {
289 if (sk->sk_hash != hash)
290 continue;
291 if (likely(INET_MATCH(sk, net, acookie,
292 saddr, daddr, ports, dif))) {
293 if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
294 goto out;
295 if (unlikely(!INET_MATCH(sk, net, acookie,
296 saddr, daddr, ports, dif))) {
297 sock_gen_put(sk);
298 goto begin;
299 }
300 goto found;
301 }
302 }
303
304
305
306
307
308 if (get_nulls_value(node) != slot)
309 goto begin;
310out:
311 sk = NULL;
312found:
313 return sk;
314}
315EXPORT_SYMBOL_GPL(__inet_lookup_established);
316
317
318static int __inet_check_established(struct inet_timewait_death_row *death_row,
319 struct sock *sk, __u16 lport,
320 struct inet_timewait_sock **twp)
321{
322 struct inet_hashinfo *hinfo = death_row->hashinfo;
323 struct inet_sock *inet = inet_sk(sk);
324 __be32 daddr = inet->inet_rcv_saddr;
325 __be32 saddr = inet->inet_daddr;
326 int dif = sk->sk_bound_dev_if;
327 INET_ADDR_COOKIE(acookie, saddr, daddr);
328 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
329 struct net *net = sock_net(sk);
330 unsigned int hash = inet_ehashfn(net, daddr, lport,
331 saddr, inet->inet_dport);
332 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
333 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
334 struct sock *sk2;
335 const struct hlist_nulls_node *node;
336 struct inet_timewait_sock *tw = NULL;
337
338 spin_lock(lock);
339
340 sk_nulls_for_each(sk2, node, &head->chain) {
341 if (sk2->sk_hash != hash)
342 continue;
343
344 if (likely(INET_MATCH(sk2, net, acookie,
345 saddr, daddr, ports, dif))) {
346 if (sk2->sk_state == TCP_TIME_WAIT) {
347 tw = inet_twsk(sk2);
348 if (twsk_unique(sk, sk2, twp))
349 break;
350 }
351 goto not_unique;
352 }
353 }
354
355
356
357
358 inet->inet_num = lport;
359 inet->inet_sport = htons(lport);
360 sk->sk_hash = hash;
361 WARN_ON(!sk_unhashed(sk));
362 __sk_nulls_add_node_rcu(sk, &head->chain);
363 if (tw) {
364 sk_nulls_del_node_init_rcu((struct sock *)tw);
365 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
366 }
367 spin_unlock(lock);
368 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
369
370 if (twp) {
371 *twp = tw;
372 } else if (tw) {
373
374 inet_twsk_deschedule_put(tw);
375 }
376 return 0;
377
378not_unique:
379 spin_unlock(lock);
380 return -EADDRNOTAVAIL;
381}
382
383static u32 inet_sk_port_offset(const struct sock *sk)
384{
385 const struct inet_sock *inet = inet_sk(sk);
386
387 return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr,
388 inet->inet_daddr,
389 inet->inet_dport);
390}
391
392
393
394
395bool inet_ehash_insert(struct sock *sk, struct sock *osk)
396{
397 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
398 struct hlist_nulls_head *list;
399 struct inet_ehash_bucket *head;
400 spinlock_t *lock;
401 bool ret = true;
402
403 WARN_ON_ONCE(!sk_unhashed(sk));
404
405 sk->sk_hash = sk_ehashfn(sk);
406 head = inet_ehash_bucket(hashinfo, sk->sk_hash);
407 list = &head->chain;
408 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
409
410 spin_lock(lock);
411 if (osk) {
412 WARN_ON_ONCE(sk->sk_hash != osk->sk_hash);
413 ret = sk_nulls_del_node_init_rcu(osk);
414 }
415 if (ret)
416 __sk_nulls_add_node_rcu(sk, list);
417 spin_unlock(lock);
418 return ret;
419}
420
421bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
422{
423 bool ok = inet_ehash_insert(sk, osk);
424
425 if (ok) {
426 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
427 } else {
428 percpu_counter_inc(sk->sk_prot->orphan_count);
429 sk->sk_state = TCP_CLOSE;
430 sock_set_flag(sk, SOCK_DEAD);
431 inet_csk_destroy_sock(sk);
432 }
433 return ok;
434}
435EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
436
437static int inet_reuseport_add_sock(struct sock *sk,
438 struct inet_listen_hashbucket *ilb,
439 int (*saddr_same)(const struct sock *sk1,
440 const struct sock *sk2,
441 bool match_wildcard))
442{
443 struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
444 struct sock *sk2;
445 kuid_t uid = sock_i_uid(sk);
446
447 sk_for_each_rcu(sk2, &ilb->head) {
448 if (sk2 != sk &&
449 sk2->sk_family == sk->sk_family &&
450 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
451 sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
452 inet_csk(sk2)->icsk_bind_hash == tb &&
453 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
454 saddr_same(sk, sk2, false))
455 return reuseport_add_sock(sk, sk2);
456 }
457
458
459 if (!rcu_access_pointer(sk->sk_reuseport_cb))
460 return reuseport_alloc(sk);
461 return 0;
462}
463
464int __inet_hash(struct sock *sk, struct sock *osk,
465 int (*saddr_same)(const struct sock *sk1,
466 const struct sock *sk2,
467 bool match_wildcard))
468{
469 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
470 struct inet_listen_hashbucket *ilb;
471 int err = 0;
472
473 if (sk->sk_state != TCP_LISTEN) {
474 inet_ehash_nolisten(sk, osk);
475 return 0;
476 }
477 WARN_ON(!sk_unhashed(sk));
478 ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
479
480 spin_lock(&ilb->lock);
481 if (sk->sk_reuseport) {
482 err = inet_reuseport_add_sock(sk, ilb, saddr_same);
483 if (err)
484 goto unlock;
485 }
486 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
487 sk->sk_family == AF_INET6)
488 hlist_add_tail_rcu(&sk->sk_node, &ilb->head);
489 else
490 hlist_add_head_rcu(&sk->sk_node, &ilb->head);
491 sock_set_flag(sk, SOCK_RCU_FREE);
492 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
493unlock:
494 spin_unlock(&ilb->lock);
495
496 return err;
497}
498EXPORT_SYMBOL(__inet_hash);
499
500int inet_hash(struct sock *sk)
501{
502 int err = 0;
503
504 if (sk->sk_state != TCP_CLOSE) {
505 local_bh_disable();
506 err = __inet_hash(sk, NULL, ipv4_rcv_saddr_equal);
507 local_bh_enable();
508 }
509
510 return err;
511}
512EXPORT_SYMBOL_GPL(inet_hash);
513
514void inet_unhash(struct sock *sk)
515{
516 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
517 spinlock_t *lock;
518 bool listener = false;
519 int done;
520
521 if (sk_unhashed(sk))
522 return;
523
524 if (sk->sk_state == TCP_LISTEN) {
525 lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock;
526 listener = true;
527 } else {
528 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
529 }
530 spin_lock_bh(lock);
531 if (rcu_access_pointer(sk->sk_reuseport_cb))
532 reuseport_detach_sock(sk);
533 if (listener)
534 done = __sk_del_node_init(sk);
535 else
536 done = __sk_nulls_del_node_init_rcu(sk);
537 if (done)
538 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
539 spin_unlock_bh(lock);
540}
541EXPORT_SYMBOL_GPL(inet_unhash);
542
543int __inet_hash_connect(struct inet_timewait_death_row *death_row,
544 struct sock *sk, u32 port_offset,
545 int (*check_established)(struct inet_timewait_death_row *,
546 struct sock *, __u16, struct inet_timewait_sock **))
547{
548 struct inet_hashinfo *hinfo = death_row->hashinfo;
549 struct inet_timewait_sock *tw = NULL;
550 struct inet_bind_hashbucket *head;
551 int port = inet_sk(sk)->inet_num;
552 struct net *net = sock_net(sk);
553 struct inet_bind_bucket *tb;
554 u32 remaining, offset;
555 int ret, i, low, high;
556 static u32 hint;
557
558 if (port) {
559 head = &hinfo->bhash[inet_bhashfn(net, port,
560 hinfo->bhash_size)];
561 tb = inet_csk(sk)->icsk_bind_hash;
562 spin_lock_bh(&head->lock);
563 if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
564 inet_ehash_nolisten(sk, NULL);
565 spin_unlock_bh(&head->lock);
566 return 0;
567 }
568 spin_unlock(&head->lock);
569
570 ret = check_established(death_row, sk, port, NULL);
571 local_bh_enable();
572 return ret;
573 }
574
575 inet_get_local_port_range(net, &low, &high);
576 high++;
577 remaining = high - low;
578 if (likely(remaining > 1))
579 remaining &= ~1U;
580
581 offset = (hint + port_offset) % remaining;
582
583
584
585 offset &= ~1U;
586other_parity_scan:
587 port = low + offset;
588 for (i = 0; i < remaining; i += 2, port += 2) {
589 if (unlikely(port >= high))
590 port -= remaining;
591 if (inet_is_local_reserved_port(net, port))
592 continue;
593 head = &hinfo->bhash[inet_bhashfn(net, port,
594 hinfo->bhash_size)];
595 spin_lock_bh(&head->lock);
596
597
598
599
600 inet_bind_bucket_for_each(tb, &head->chain) {
601 if (net_eq(ib_net(tb), net) && tb->port == port) {
602 if (tb->fastreuse >= 0 ||
603 tb->fastreuseport >= 0)
604 goto next_port;
605 WARN_ON(hlist_empty(&tb->owners));
606 if (!check_established(death_row, sk,
607 port, &tw))
608 goto ok;
609 goto next_port;
610 }
611 }
612
613 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
614 net, head, port);
615 if (!tb) {
616 spin_unlock_bh(&head->lock);
617 return -ENOMEM;
618 }
619 tb->fastreuse = -1;
620 tb->fastreuseport = -1;
621 goto ok;
622next_port:
623 spin_unlock_bh(&head->lock);
624 cond_resched();
625 }
626
627 offset++;
628 if ((offset & 1) && remaining > 1)
629 goto other_parity_scan;
630
631 return -EADDRNOTAVAIL;
632
633ok:
634 hint += i + 2;
635
636
637 inet_bind_hash(sk, tb, port);
638 if (sk_unhashed(sk)) {
639 inet_sk(sk)->inet_sport = htons(port);
640 inet_ehash_nolisten(sk, (struct sock *)tw);
641 }
642 if (tw)
643 inet_twsk_bind_unhash(tw, hinfo);
644 spin_unlock(&head->lock);
645 if (tw)
646 inet_twsk_deschedule_put(tw);
647 local_bh_enable();
648 return 0;
649}
650
651
652
653
654int inet_hash_connect(struct inet_timewait_death_row *death_row,
655 struct sock *sk)
656{
657 u32 port_offset = 0;
658
659 if (!inet_sk(sk)->inet_num)
660 port_offset = inet_sk_port_offset(sk);
661 return __inet_hash_connect(death_row, sk, port_offset,
662 __inet_check_established);
663}
664EXPORT_SYMBOL_GPL(inet_hash_connect);
665
666void inet_hashinfo_init(struct inet_hashinfo *h)
667{
668 int i;
669
670 for (i = 0; i < INET_LHTABLE_SIZE; i++) {
671 spin_lock_init(&h->listening_hash[i].lock);
672 INIT_HLIST_HEAD(&h->listening_hash[i].head);
673 }
674}
675EXPORT_SYMBOL_GPL(inet_hashinfo_init);
676
677int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
678{
679 unsigned int locksz = sizeof(spinlock_t);
680 unsigned int i, nblocks = 1;
681
682 if (locksz != 0) {
683
684 nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U);
685 nblocks = roundup_pow_of_two(nblocks * num_possible_cpus());
686
687
688 nblocks = min(nblocks, hashinfo->ehash_mask + 1);
689
690 hashinfo->ehash_locks = kmalloc_array(nblocks, locksz,
691 GFP_KERNEL | __GFP_NOWARN);
692 if (!hashinfo->ehash_locks)
693 hashinfo->ehash_locks = vmalloc(nblocks * locksz);
694
695 if (!hashinfo->ehash_locks)
696 return -ENOMEM;
697
698 for (i = 0; i < nblocks; i++)
699 spin_lock_init(&hashinfo->ehash_locks[i]);
700 }
701 hashinfo->ehash_locks_mask = nblocks - 1;
702 return 0;
703}
704EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);
705